Means for distributing liquids very finely



Dec. 25, 1956 K. scHUTz MEANS FOR DISTRIBUTING LIQUIDS VERY FINELY FiledNov. 22, 1952 1 v l xll 0 m 0 I an KuR'f ScHUTZ \NVE NTOE, QULMS I'E (b1A-rws.

United States PatentO MEANS FOR DISTRIBUTING LIQUIDS VERY FINELY KurtSchiitz, .Vevey, Switzerland, assignor to Berthoud & Cie,Vevey-Corseaux, Switzerland, a corporation of This invention relates tomeans for distributing liquids very finely. The object of the inventionis to enable liquids to be distributedvery finely without the assistanceof atomiser nozzle-s.

According to the invention, distributing liquids very finely by means ofa distributor tube and discharge tubes arranged at an angle to thelatter, is characterisedin that air and liquid in atomised form areblown longitudinally' under positive pressure through the distributortube into the discharge tubes where the liquid is distributed as a filmon the insidewall of the discharge opening under the influence of theflow velocity of the air in asection of the discharge tube of differentcross section, and that this film is broken up into very fine particlesat the edge of the opening and flows away with the air. In thisoperation, the atomised liquid is deposited in uniformly dividedformover the length of the distributor tube and on the inside wall thereofand flows into the discharge tubes of the distributor tube. Due to thecontact with the internal wall of the distributor tube, the droplets areagain united into a film of liquid or into tncklespdrops or waves andpass in this form into the discharge tubes. I

I A further development of this invention has led to a constructionalform in which theliquid entering the discharge tube is reliasblyconductedto the edges of the outlet opening as a uniformly divided filmof liquid and in which this liquid film can be blown out as very finedroplets at the edges'of the outlet openings of the discharge tube.

The invention therefore further comprises means for distributing liquidsvery finely comprising a distributor I tube and discharge tubes arrangedat an angle to the latter and means for supplying air and liquid inatomised form under positive pressureto the distributor tube, thedischarge tubes havingan enlarged. cross section concentric with thedischarge tube axis between the discharge opening and the distributortube for the purpose of formliquid on the edges of the opening.According to a further development of the invention, the uniform liquidfilm issuing from the annular enlargement is moved over radiallyextending teeth which are arranged on the edges of the opening, and theliquid is advanced up to the tips of the teeth along the flanks thereof,which are inclined towards the center of air stream, in order to bedetached therefrom as liquid droplets and to be carried along by thestream of air. In order to carry this process into effect,,the teetharranged on the edge 2,775,482 Patented Dec. 25, 1956 the tube axiswhich are disposed externally of the tube.

As a result of the sudden annular enlargement of the outlet openingswith a following constriction thereof to substantially their originaldimensions, there is reliably achieved the eifect that (in the casewhere the liquid is moved forward in the discharge openings in the formof trickles) the liquid is detached by the change in pressure conditionson flowing through the annular enlargement and a liquid film is formedwhich is uniformly distributed over the whole of the edge of the outletopening. This film can then be brokendown into extremely fine dropletsor, in accordance with the present invention, can be detached in theform of fine droplets of liquid from the tips of the teeth arrangedradially at the edges of the opening. This form of extremely fineatomisation is particularly advantageous because there are no movingparts and consequently there can be no wear. on the outlet openings. Thedischarge openings are circular and provide an'enlarged free passage tothe air. By this means the frictional losses 'are reduced, so that theemission energy is substantially increased, this being particularlyadvantageous, for example, when it is a question of penetrating a plantcrop when combatting animal and fungoidal pests. In order that. theinvention maybe clearly understood, one embodiment thereof will now bedescribed by way of example with reference to the accompanyingdiagrammatic drawing, in which:

Figure 1 is a longitudinal section through a distributo tube and itsdischarge tubes, I

Figure2 is a longitudinal section through a discharge tube to a largerscale, and

Figure 3 is a cross-section on the line IIIIIIof Figure 2.

In Figure 1, 1 represents the elongated distributor tube, into whichcompressed air is introduced at 2 and the liquid at 3 through a bentpipe. An atomiser device 4 effects the atomisation of the liquid beingsupplied for the purpose of the lengthwise distribution thereof by theair-stream in the elongated distributorpipe 1. A number of dischargetubes 5 are arranged adjacent one another and at an angle to thedistributor tube.

As shown in Figure 2, each discharge tube 5 consists of a cylindricaldelivery tube 6 with a sudden enlargement in the form of an annularchamber 7 and a cylindrical discharge opening 8 which is constrictedagain, the edge of said opening having provided thereon radiallyarranged teeth 9, which are shown in plan view in Figure 3.

The effect which it is desired to achieve is to supply the liquid to theoutlet opening 8 as a uniform film, that is to say, the film should havean equal thickness at the places marked 10 and 11. If the liquid in thedischarge tube 6 has not formed a uniform film but reaches the outletopening as a trickle 12 without being distributed on the internal wall,the annular chamber 7 effects a uniform distribution of the liquid onthe circumference by the sudden enlargement of the tube cross section.The air flowing at high velocity through the tube 6 undergoes a suddenreduction in pressure in the sudden enlargement formed by the chamberwhich reduction effects the breaking-up and distribution of the liquid.Following the pressure drop, the liquid, for example in the form of thetrickle 12, flows into the annular chamber and fills this completely.The ring of liquid formed in this manner isgiven an eddying motion inthe direc- 'tion of the arrows "13 under the action of the air flowingpast. Since liquid continues to flow, the stream of air carries with itthe same quantity of liquid from the inside diameter of the liquid ringand thus produces at 10 and- 11 in the discharge tube 8 the liquid filmwhich is distributed uniformly on the circumference. v

The liquid which is uniformly broken up and distributed in this manneris then led to the of the opening by the air stream, converted intoextremely fine droplets and carried along by the air stream.

If this "conversion of the liquid'fihh is to be carried out by means ofthe radial teeth according to the invention, a uniform distribution ofthe liquid film as at 1'0 and 11 is not absolutely necessary. Theatomisation at the outlet then takes place in the following manner. Theair, which is flowing to atmosphere at a high velocity also through theslots 14 between the teeth 9, produces an eddy on the flank surfaces'ofthe teeth and consequently a zone of reduced pressure. Under the actionof the stream of air, the liquid also passes through between the teethand, following the pressure drop, flows into the zones of reducedpressure on the flanks of the teeth. Since the radially extending toothflanks are slightly inclined in the direction of the stream of air, theliquid travels to the tips of the teeth. The'deta-chnient of the liquidin extremely fine droplets now occurs on the tips of all teeth, becausethe point of detachment is acted upon on all sides by the stream'of air.An air pressure of 200 to 300 mm. water column is adequate for carryingoperation into effect.

It is essential for the purpose of the apparatus that the teeth 9 on therim of the opening are radially disposed and outwardly inclined, andthat their height at the wall of the opening, measured in the directionof the tube axis is greater than the tooth width measured in thedirection of the circumference of the tube, and that the radiallydisposed flanks of the teeth 9 are directed towards points of the tubeaxis which are outside the tube. The apparatus according to theinvention for the distribution of liquids by at least one sudden annularenlargement and teeth arranged radially on the edges of the opening canbe used for the breaking up and 'atomisation of any liquids, for examplethe atomisation of liquid in oil burners or the like.

What I claim is:

1. Means for distributing liquids very finely comprising a distributortube and discharge tubes having discharge openings arranged at an angleattached to the latter and means for supplying air and liquid inato'mised form under positive pressure to the distributor tube and tothedischarge tubes, each of the discharge tubes having an enlarged crosssection concentric with its axis and located between the dischargeopening and the distributor tube for the purpose of forming a film onthe inside wall of the tube, and the edge of the opening having teethclosed at one end, a series of closely spaced nozzles aligned in anaxial direction along said tube, means to feed with compressed air theopen end of said tube and means to atomize liquid into said air at apoint upstream with respect to all of said nozzles, whereby the liquidatomized in said compressed air is deposited throughout the length ofsaid tube on the inner wall thereof in a thin liquid formation which isfed into said nozzles, the latter being provided with terminal edgesadaptedto break up at least part of the liquid formations thus fedthereto into a succession of formations of fine droplets correspondingto a subs'tantially uni-form rate of delivery from each nozzle and thecross-sectional area of each nozzle being greatly in excess of thecorresponding area of the liquid formation passing through said nozzle,whereby the stream of air is divided into jets of substantialcrosssection by passing through said nozzles, each such jet successivelyentraining said formations of droplets, while giving the same aconsiderable kinetic energy, the outlet of each one of said nozzlesbeing provided with an annular row of teeth extending radially inwardand downstream, whereby the formations of liquid fed to said outlet flowalong said teeth, While being split up into droplets, and whereby thedroplets thus fed to the points of said teeth are embedded in said airjet and thus imparted with a considerable kinetic energy, and each oneof said nozzles being provided, upstream said row of teeth, with anannular eddy chamber whereby substantially uniform distribution of theliquid formations fed into said nozzle is effected.

5. A spraying device according toclaim 4, in which said eddy chamber isconstituted by an integral portion of enlarged diameter of said nozzle.

References Cited in the file of this patent UNITED STATES PATENTS-394,921 Hallowell Dec. 18, 1888 1,441,425 Jackson Ian. 9, 1923 1,462,395Thomson July 17, 1923 2,029,337 Parker Feb. 4, 1936 2,285,831Pennypacker June 9, 1942 FOREIGN PATENTS 602,404 France Mar. 18, 1926

